I searched on the home page for the region Myriam, using Fabaceae, south-east, and Atlantic rainforest in the search brought up only a few.
It does look like the only option. I wonder if you could contact the botanical gardens to see what they say?
Interesting article you found, I have learnt not to place too much importance on flower, leaf, or the whole plant form. Remember the tropical looking tree which was in the nettle family?!
